This invention relates to friction rotors for the false twisting of synthetic threads.
Utilization of friction rotors or disks for the production of false-twisted synthetic threads by utilizing a so-called false-twisting unit is generally known. Typically these friction rotors are constructed of a PUR-plasma-coating full ceramic or a nickel-diamond coating. In comparison with a nickel-diamond coated rotor, the life of a PUR-friction rotor is very short. As a practical matter, regeneration of these friction coverings is impossible.
The prior art has attempted to design a so-called throw-away disk for false-twisting of synthetic threads constructed so that the central base support portion of the disk can be reused. Federal Republic of Germany OS No. 29 01 408 describes a friction rotor which comprises a support part and a replaceable friction covering ring. Unfortunately, it has been found that with increasing speeds of rotation the friction covering ring in the construction of German OS No. 29 01 408 becomes loose from the support so that it no longer assures satisfactory operation of the false-twisting unit.
German Utility Model No. 76 23 421 discloses a friction rotor in which there is a shrink connection between the friction covering and the base support. Use of a shrink connection makes it inconvenient to replace a worn part, and with a shrink connection the friction covering loosens from its support as a result of temperature changes, different coefficients of expansion of the materials, and the action of corrosive scrooping agents. In the case of a three-part disk in which the support is placed on a sleeve, it has been observed that the latter becomes detached from the support after a relatively short period of operation.